1. Field of the Invention
The present invention relates to a device for detachably mounting, on a backing member, interchangeable rubber type or type made of a similar resilient material. The invention can be used to advantage either with conventional hand-stamping devices or with more advanced, rotary printing devices.
The type of rotary printing application in which the present invention may be used to best advantage is illustrated in U.S. Pat. No. 3,128,700 to L. S. Kunetka and U.S. Pat. No. 2,771,031 to R. W. Knapp. These patents both describe the use of rubber print in connection with rotary printing drums or rollers. As discussed in the Kunetka patent, rubber print is particularly useful in the art of printing upon certain types of sheet materials, such as corrugated cardboard or the like, which may be crushed by more conventional metal printing plates.
In either a hand stamping or a rotary printing application, the kind of fastening, retaining or mounting device which can be used successfully is rather restricted. First of all, it is important that no part of the mounting device project outwardly from the body further than the distance which the print characters protrude therefrom. Secondly, it is important and desirable that the printing members be easily attachable to the body of the device in a very secure manner whereby the lateral forces exerted during a printing or stamping operation will not loosen or displace the printing members from the body of the device. Thirdly, it is important that the printing members be readily detachable from the device so that the printing characters may be interchanged and rearranged and so that reattachment thereof may be readily accomplished. Fourthly, the arrangement should be such that the same basic elements may be used repeatedly, these elements also being capable of use in different printing and/or stamping applications.
2. Description of the Prior ARt
Devices for mounting a plurality of interchangeable rubber printing members have theretofore been proposed.
U.S. Pat. Nos. 3,099,213, 2,962,964, 2,877,707 and 2,859,694, all to W. K. Munson, disclose stamping devices wherein a plurality of rubber printing members are guidably strung onto one or more elongated rods or bars which, in turn, are secured at each end thereof to the body of a stamping device. In each instance, the arrangement of components for fastening the rod or bar to the body of the stamping device is relatively complex and/or costly, particularly when compared with the very simple and inexpensive device of the present invention. Moreover, the fastening means disclosed by each of the above patents is not readily adaptable to different printing or stamping applications. For example, none could be applied in a practical and advantageous manner to rotary printing applications. Furthermore, all of the devices disclosed in the foregoing patents are intended only for securing metal rods or bars of relatively large cross-section to the body of the stamping apparatus. None would be suitable for fastening a thin, flexible band to the body of a stamping or rotary printing device. The use of such a band in connection with rubber printing elements has special advantages which will be described hereinafter.
U.S. Pat. No. 2,222,333 to Wenzel et al. discloses a system for mounting rubber type to a base member. Both the type itself as well as the base member have a plurality of complementary, interlocking, parallel ridges. The fact that each of the many ridges associated with a single piece of type must be pressed within the corresponding grooves between the ridges of the base member, makes the assembly or composition of plural printing members a rather time consuming operation. This is particularly so in view of the ease and speed with which slotted rubber pieces of type can be strung onto a band, and the facility with which the band, in turn, may be snapped into place on a backing member.
Of course, in an application wherein the type-holding arrangement of Wenzel et al. is used, the printing apparatus must be shut down during the entire time required for rearranging another set of type elements to print different information in a new printing operation. With this system it is not possible, during one printing operation, to completely rearrange the type for the next operation.